For what it's worth, I was (seemingly) randomly encountering the copy/paste fail with tables. I selectively closed everything I was running and found IE (version 8) to be the culprit. Once I closed it I could copy/paste at will. When I started it back up, c/p fail. And so on, every time.

Macropod, you've cleared up something that's been troubling me mightily for several days. I would never have made the connection between installing Skype and the change in pasting tables. I'm so grateful!